09.2018 - New chassis, new luck. Finally KW Variant 3!

Since 13 September 2018, just in time for GLP 5, the C30 has been equipped with a KW variant 3 threaded chassis. Although the BILSTEIN B14 was still in working condition, but it was increasingly noticed that the B14 is not optimal for the C30. Before I come to the KW V3 suspension, I would like to share my personal experience with the Bilstein B14 threaded suspension.


First of all it should be noted that this is my personal experience and does not necessarily apply to everyone who has installed this suspension.


Before I have installed the Bilstein B14 in March 2018, the C30 was equipped with Eibach lowering springs were in combination with the dampers from the original r-Design sports suspension. In this combination, which was used for about 4 years, there were no problems with the drive shaft sleeve or the dome bearings. When exchanging the chassis everything was fine with the car, a wear of the mentioned parts was not foreseen.


After 3 months with the B14 chassis it turned out that the drive shaft sleeve was completely destroyed and the dome bearings also suddenly made unpleasant noises. What was strange about the matter, however, was that these signs of abrasion had been observed at Daniels C30 for several years.

The Bilstein in Daniel's C30 has been in use for 8 years and 77,000 kilometres before it was replaced by a KW chassis due to the problems mentioned above.

With Daniels C30 the drive shaft sleeve and the dome bearings had to be renewed annually. This matched my suspicion that the B14 might be involved in the wear. In addition it has to be said that Daniel with his C30 did not drive on the race track and also not in daily business in this time. My C30 has only seen 3 events on the Nordschleife and no daily use. In addition, the B14 was not bad in principle, but one noticed quickly that it is not intended for use on the racetrack.


The C30 was much too immersed and showed a very unsteady handling on the Nordschleife. It was clear to me that you can't expect a racing suspension in this price segment, but I expected something more. Increasingly it was noticed that the B14 was rather designed for the models V50, S40 and the matching Ford models. An indication for this assumption is among other things the fact that the Bilstein uses the same spring/damper combination for all models. If you are familiar with the technical data of the models, you know that the C30 has different axle loads and therefore needs a different suspension setup. Some manufacturers do this, but not all! For all these reasons I have decided to use a different chassis.


I didn't have to think about it for long, it should definitely be a KW suspension. The quality and the customer service are excellent, especially since the suspensions are individually adapted to the model - i.e. the suspension for the C30 has dampers and springs corresponding to the axle loads.  I have talked for a long time with an employee from the technical development department, because I had some questions due to the previous experience with the B14. So it was clear, the C30 gets a KW variant 3 chassis. Although I would have liked to have a Competition suspension, but everyone knows that the money does not grow on trees.By the way, I would like to mention that the KW variant 3 chassis now has its own dome bearings! That was probably not the case so far and could also solve the dome bearing problem.


The KW suspension has been installed for about 2.5 months now and has already completed several laps of the Nordschleife - in the basic setting so far.

I am simply impressed! The C30 lies like a board on the track, reacts perfectly and doesn't dive into the curves as extremely as before. Closed and fast sections on the Nordschleife can now be driven through significantly faster and also more safely.

Due to the KW V3 the C30 has got much more smoothness in handling, the nervous tail is also history. Now it's only up to the tires and other small things to get the absolute optimum out. The KW V3 has also proven itself in daily use. You shouldn't forget that it is harder than a normal suspension, but the V3 is comfortable even on longer trips and calms down quickly on the wavy road surfaces of the German highway.


The next steps for 2019 are therefore to procure appropriate tyres, install additional chassis struts and possibly replace one or the other bearing with PU. Then we will continue to approach the newly set limits and have the suspension specially adjusted.


Finally a before and after picture. With the KW V3 the C30 is much more saturated on the road, the rear looks much more harmonised. The V3 is by the way not yet at its lowest setting. That would be rather a disadvantage on the race track and is optically not my case. 


Picture by Charleen Rümling
Picture by Charleen Rümling

03.2018 - Finally sporty on the road with the Bilstein B14!

Just in time for the start of the season the C30 finally got the BILSTEIN B14 coilover suspension. The change to a reasonable sports suspension was also imperative in view of the Nordschleife, which announced itself for April. Although I was very satisfied with the optical lowering of the previously installed Eibach springs, this was not ideal for the standard dampers. According to the expert opinion, the Eibach Pro-Kit lowers the C30 by 40mm at the front and 20mm at the rear, which is why it is basically also possible to continue using the standard dampers. However, after setting this resulted in a loose lowering of 50mm at the front and 30mm at the rear axle. This overtaxes the standard dampers of the R-Design chassis, which is particularly noticeable when driving over bumps at higher speeds and when excitations occur in quick succession. This leads to permanent seesawing of the body, which is not unsafe on the motorway, but uncomfortable and also simply annoying. The same behavior can be seen in fast cornering. The C30 quickly became restless and simply no longer felt taut. But thank God we came across a little used B14 over the winter, which was now ready for installation.

Actually, there's always something wrong when changing the landing gear. Usually tight screws get on your nerves, or you notice when disassembling that other parts should be replaced. Contrary to these expectations, however, the chassis was changed quickly and without any problems. Only for the suspension struts at the front axle some encrustations had to be ground away by hand. Thanks to our buddy's experience with screwdrivers, the chassis including the new dome bearing (thanks to Skandix) was permanently installed.

An info at the edge to the dome camps in the P1 platform.

If you don't know yet - there are two different dome camps. On the one hand, the completely normal standard chassis dome bearing and the dome bearing from the R-Design chassis. According to Volvo, the cathedral bearing from the R-design chassis should be more durable if a sports suspension is installed and can cope much better with lowering. From my own experience I can say that this statement seems to be true. Daniel had used the standard cathedral bearings in his C30 in combination with the BILSTEIN B14 for years. It had a very high wear on dome bearings, as the normal design apparently has problems with the sports shock absorbers.

In the meantime I played with the idea of using Uniball dome bearings (K-Sport has suitable ones on offer), but so far I could not get myself to this attempt.

The reason for this is the 520 km long journey to and from the Nordschleife. For this reason, the C30 must remain suitable for everyday use. Some have reported that the Uniball dome bearings are associated with a loss of comfort. For the time being, therefore, we will stick to the solution with the series parts. Maybe I'll test that with the next chassis, which I'm sure will come sometime.

In the meantime, the suspension has already unwound several thousand kilometers, 330 km of which are on the Nordschleife.

The BILSTEIN B14 is very solid and sporty in everyday use as well as on circuits, without being shaken too much by the often bad German roads. Often one reads in the net that the rear becomes restless and the B14 is not optimally adjusted to the C30. However, I cannot confirm this opinion. On the contrary - on the Nordschleife I never had the feeling that the rear was restless. Especially in the fast exchange curves after the carousel on the way to the Brünnchen, the C30 with the B14 is very taut and safe, and that despite the upper and lower struts on the front axle. For the entry level and in the price range, the B14 is a very good alternative to lowering with springs alone, because the handling is significantly rounder and also safer than with the too deep Pro-Kit described above or the standard suspension that is too soft for sporty purposes.


But why not a KW chassis or e.g. the two-way BILSTEIN B16?

First and foremost, this is an economical decision if you get a used, high-quality chassis in good condition for a fraction of the price. The main aim here is to work out step by step which changes fit to the C30 in order to cope with the long journeys and the tests on the Nordschleife at the same time. We have to budget in order to be able to cover the topics of brakes, wheelset, other chassis parts, engine peripherals and wear in the best quality at the same time. Every Volvo driver who has ever dealt with these topics knows the situation that the selection for our brand is narrow and the prices are high. That's why, and to get into the project without frying everything for a construction site and firing cannons at small moose, the decision for the "small" solution.
As soon as I have more circuit experience and, above all, the need for an upgrade is growing because I can drive the C30 much more frequently and safely at its limits, it certainly makes sense to tackle the chassis issue again. More quality for the price is not possible at this point, however, in our opinion.


But it would still be much cheaper. Suspensions, also height-adjustable, are now available from some manufacturers for less than the used price of a BILSTEIN B14. As the GLP is held on the Nordschleife and the "green hell" is rightly regarded as one of the most demanding routes for crew and equipment, safety has the highest priority. Each run we do about 250km on the Eifel roller coaster. This is probably the fourfold equivalent on the road. Call it old-fashioned, but we prefer to rely on brands that have been testing there for decades and in many cases are original equipment manufacturers for sporty production cars and racing teams. Especially on this stretch of road, the best solution is a chassis with a proper residual spring travel that also withstands the vibration sections and road surface changes well and keeps the tires permanently and safely on the road. The first look at the vehicles in the queue for technical acceptance showed that we have taken the right step.


Finally, I would like to refer to two very interesting articles by Bilstein:
Firstly, the article on "Why no-name air spring modules pose a safety risk". This article describes in detail where the quality differences are and why no compromises should be made when it comes to suspension:

The second article deals with chassis and chassis technology. The article gives an insight into the basic knowledge of the function of shock absorber and spring:

Enjoy your reading!


Pictures by Charleen Rümling

10.2014 - Get low...

Despite the r-design chassis, the C30 seemed to be more like an XC30. Although the chassis is not the worst, there is still a lot of air up there. The Eibach springs with a lowering of 30 mm according to the expert opinion offer a quick and cost-effective solution. Until now, these are still installed together with the standard dampers, because I didn't see any need for more in everyday life.
From experience I can say, however, that the C30 is considerably lower than 30mm and other dampers are certainly more sensible. However, as I would like to devote myself more intensely to the subject of suspension until the 2018 season, the standard dampers will remain in this combination for the rest of the time.
Up to now, the series dampers have also taken part in everything without stance, and meanwhile for 2 years with quite sporty driving style.
Following a figurative proof of how much the change of springs affects the appearance:

Pictures by Charleen Rümling (left) and Jens Horstmann (right)